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Thank you for the shuttle RTF updates. The NASA people are doing their darndest to make Discovery safe and ready for its May (?) launch date. The unresolved question is how long the shuttle can last. Can we go accident-free through 2010? Try as they might, the shuttle was never a good concept and NASA will never achieve acceptable safety margins.
If James Oberg's recent report is correct, Zenit is the preferred booster for Kliper. The modified R-7 (Onega) is one of two designs that will serve as a Russian fallback for the Ukranian-built Zenit. Perhaps an Angara variant is the other backup.
*Is it just me or does this seem like more of a volatile subject than I'd anticipated??
It's surprisingly volatile. There are entire advocacy groups dedicated to stopping Mars Sample Return. I also believe that the curmudgeonly space editorialist Jeffrey Bell is of the mindset that if Mars has life, we should not send humans there. Then again, Bell seems to oppose all human spaceflight.
Here's a piece from the Times http://www.timesonline.co.uk/article/0, … ml]raising the possibility of Mars life threatening earth.
Keith Cowing of http://www.nasawatch.com/archives/000421.html#more]NASA Watch has a good rebuttal, contrasting the quote used in the article with the article and context it originally came from.
We don't need people making claims of extreme danger from Martian microbes on earth. Do we need to contain Martian samples if we bring them to earth? Yes. Is this doable? Yes! But we don't need people saying that containment is an impossibility and that Mars Sample Return should never happen.
Zeal can be a good thing (as Zubrin explicitly says in "Case for Mars,") but I fear that the Mars Society could just become a cult made up of Zubrin's yes-men and lose sight of the larger goal: putting humans on Mars.
Mars Direct, as an intellectual exercise at creating a minimalist Mars Mission, was a tremendous step towards getting us to Mars. But while it should inspire better mission design than the Battlestar Galactica ship of old, we should not dogmatically adhere to it.
Zeal + In situ resource utilization + nuclear thermal rockets + closed loop life support + a realistic number of crew for the science mission + conjunction-class trajectory = a successful formula for putting humans on Mars.
I too believe that Mars Direct is too optimistic in its mass budgets. I knew some people who took part in the Kepler competition, and they said so explicitly. I haven't read their report yet, but I soon will, and I doubt the verdict will be pretty regarding the feasibility of Mars Direct.
One problem he has acknowledged is that pressurized rovers require more mass than is available in the Hab.
If you've ever seen the artwork for James Cameron's Mars project, the famed movie director comes up with a novel solution: land the crew inside the pressurized rover.
Is it workable? Who knows. But at least we have people thinking about innovative design techniques that deserve to be studied.
4) If NASA insisted on a six man crew per mission, how much larger would his Ares type booster need to be to get the job done?
In NASA's original Design Reference Mission, a 200 MT booster is specified. The booster chosen was a Saturn V-derivative sometimes referred to as "Comet." It would have two strap-on boosters (each with two F-1's,) six J-2's on stage 2, and a wider 3rd stage. In the end, it doesn't look much like a Saturn V aside from the same diameter tankage and same types of engines.
In later versions of the DRM, the Comet was replaced with Magnum, an in-line SDV. Orbital Sciences' VSE proposal shows a similar booster. Magnum would only lift 80 MT, and the spacecraft and its TMI stage would be launched on separate Magnums (meaning six launches instead of three.)
In reality, I think any exploration beyond Earth orbit will have to be a series of "stunts" that we lobby for each individually.
My hope is that a series of successful "stunts" like the X-Prize and the Bigelow Prize will convince people that space is here to stay. At some point, "the powers that be" must observe that space is not a stunt, but the future of mankind.
I would prefer to not think about a "cheap and dirty" Mars mission. I would rather spend the time and money doing things correctly.
As it stands, I consider Mars Direct to be the cheapest, dirtiest Mars mission that is viable. If Mars Direct were to be improved, I would start by
1) replacing the chemical TMI stages with nuclear thermal ones
2) expand the crew compliment to six
3) use a truss for artifical gravity,
4) use either a bigger booster or break the ship down and use two Shuttle-C type boosters, and
5) go to a semi-direct architecture with a Mars-orbit rendezvous.
I too am afraid that NASA will cut corners when it comes to shuttle safety. The twenty-some flights required to complete the ISS by 2010 is a very tough hurdle and I feel that NASA will drive itself towards another accident if it pushes too hard.
My proposal is that ISS should be cut back to the point where it could be finished by 2010 if NASA adopts a four-flights-per-year rate from 2006-2010. If NASA can safely launch five flights per year instead of four, it can retire the great white albatross early and save some money that can be put towards CEV. If NASA sticks with four flights a year, they will not have to cut as many corners and have a better chance of safely ending the program on schedule.
The secret to happiness and success is setting low standards...
With all the controversy surrounding the cancellation of the last Hubble repair mission, there is one question that isn't being asked enough. How much would it cost to build a new telescope, and would it be competitive with the cost of a Hubble repair?
I don't think it would be too expensive to build another Hubble. The original Hubble was allegedly based on the KH-11 spy sat. Why couldn't we modify an in-production spy sat, add the already-built instruments intended for Hubble, and launch it on a Delta IV heavy?
Of course, that approach is mired in the old and inefficient ways of thought. Using foldable mirrors, we could build much smaller space telescopes that could be launched on smaller rockets like Pegasus. These would cost even more to develop than Hubble II, but it would result in a series of inexpensive small-sat telescopes. Rather than doing a repair mission, they would simply be de-orbited and replaced with new telescopes when their lives expire.
I have a lot of doubts about the DaVinci project, from the flimsy balloon to the inflatable re-entry cone to the fact that they want to shoot for space on the first launch rather than a series of flights that successively push the flight envelope until it goes beyond the 100 km mark.
Really, I fail to see why they need a balloon to launch the rocket. A carrier aircraft provides an initial velocity to the spaceship (like in SpacShipOne,) but DaVinci's balloon will not give the rocket an appreciable initial velocity. The key to achieving spaceflight is not altitude, but speed.
If the DaVinci team decides to adopt a realistic testing program, and if the balloon launch works as advertised, they may still be able to beat the Canadian Arrow into space as Canada's first spacecraft. That's not to say the Arrow's design is safer; I generally like it, but I view their all-liquid engines as higher-risk than the hybrids of SS1 and the DaVinci Wildfire.
I find his dislike of the JSF, which is a DoD project, to be really irrelivent to this topic though as NASA and spaceflight has nothing to do with it really, and he is much too quick to heap unwarrented praise on the Russian rockets, particularly the old ones.
Ditto.
Jeff Wright apparently believes that the fiscal pie is finite. He would cut the JSF and NASA Discovery missions to pay for his HLLV. But can't a case be made that JSF is a pressing need? Or Discovery missions are a pressing need?
The pie is not really finite; our government rarely runs on a balance budget, and if a program can be justified the funds will be found. NASA, for its part, should cut the fat. Sean O'Keefe has done a prettty good job of this, but more can always be found. Private money can also be added to the picture. If United Space Alliance could get a commercial market for Shuttle C, maybe they could develop the rocket instead of NASA. The key is not exploiting an existing need, it is creating a new need.
There ought to be a water/polymer/aluminum "inner core" the astronauts would sleep in, doubling as storm cellar and reducing flight radiation doseage... Heavier? More expensive? Sure, but its this kind of thing thats worth it... You won't have Mars dirt to shield you to and from where cosmic rays are strongest.
Studies have repeatedly shown that polymers like polyethylene would make the best shielding for the spacecraft to protect it from the harsh radiation of deep space. I think this is another example showing why Mars Direct needs to be fleshed out more.
The more we learn about Mars, the more we must add to the plan, and the more unrealistic it becomes. Will we have to switch to a 200 MT to LEO rocket to launch it all, like NASA proposed in the 1993 DRM? Should we take the high road of really big rockets, the low road of many EELVs, or the moderate road of ~80 MT boosters? I still favor the SDV, and I still support something like the Stanley Borowski "bimodal NTR" plan for getting to Mars.
All good points, GCNRevenger. I'm not one to totally discrard hydrogen, just use it where it can result in cost savings and reusability superior to kerosene.
I really liked the MAKS spaceplane because it promised to use both kerosene and hydrogen. The engineers had apparently figured out a scheme that would combine the best properties of both fuels: high thrust of kerosene when the spaceplane launched, switching off to higher-Isp, lighter hydrogen when the vehicle gained altitude. I'm sure this was a thorny problem for the engineers, and I don't know if they completely solved it, or whether the RD-701 engines were even tested.
On the topic of crew size:
Has anybody considered the prospect that some of the astronauts may not becoming back from Mars? There are a good number of chances that an individual astronaut could be killed, particularly on the rugged surface of Mars, or from cancer or another disease while on the ship. If you lose a person or two, will the Mars Direct crew be able to make it back? It takes two people to run the ISS as it is, so this seems unlikely.
It's like the Apollo 18 scenario in James Michener's fictional book "Space." I won't ruin it for you, so I highly recommend you read it for yourselves.
I don't like hydrogen as a rocket fuel. It burns more cleanly and with a higher Isp than kerosene, but it's also a lot more expensive, more difficult to store, and it makes your fuel tanks a lot bulkier and heavier.
There are a few applications where hydrogen makes sense. Small upper stages are a good use. If SSTO is possible, it would need hydrogen fuel. But aside from that, kerosene is an easier solution.
25 tonnes is still nothing to sneeze at. It's in the same class as the Titan IV and Delta IV heavy (ditto on the space shuttle, excapt that the shuttle also lifts the gross weight of the massive orbiter.)
The new rocket may allow China to build a moon ship in three or four flights, it could be adapted into a true heavy lifter, or it could expand China's knowledge base before they build an all-new heavy lifter. It also allows them to launch a true, reusable space plane, should they choose to abandon capsules for their space station.
This is a wise call by Chinese officials. Should they succeed, the bold move will pay off.
It is simply not practical to build a shuttle-derived vehicle of any sort with a LEO payload much higher than 120MT, which makes the MarsDirect mass margins pretty small. Dangerously small. If somthing turns out to be heavier then the plan calls for, and Ares can't handle it, the whole idea is sunk. MarsDirect ought to call for a 150MT minimum launch vehicle, which would make for a very comfortable margin.
Hear, hear!
I tend to think that launching it all in one shot is not a very good idea to begin with. As Dr. Benton Clark of Lockheed Martin's Mars group points out, it's good to have time in low earth orbit to check out all of the systems before you launch to Mars.
Right now I favor building a minimally-modified Shuttle C that can put 80 tonnes in LEO. Two launches would put up an 80 tonne spacecraft and an 80 tonne Mars injection stage. A third launch, this time with an EELV, can put up a Crew Exploration Vehicle that can take the astronauts to their waiting ship (as the Shuttle C would not have an escape tower.)
For the other elements in the plan (Mars Ascent Vehicle and the orbiting ERV,) two Shuttle C launches will be needed for each element. The pieces would be docked with their Mars injection staged under remote control from earth, just as the pieces of Mir were.
Assembly in space doesn't have to be painful as long as it's kept to a minimum and the shuttle is left out of it.
At first glance, Space Dev's proposal looks like a safe, yet innovative plan. It matches the established aerodynamics of the X-34 with their proven, safe hybrid motor technology. In fact, this proposal has been around on the net since arund April 2003, before Space Dev had gained fame with their SpaceShipOne motor.
Already, I see a downside. Wings on a space launch vehicle are, at best, a necessary evil. On the X-34, the wings were sized to pitch the vehicle up while its tanks were full and the engine was burning. Space Dev's vehicle will not need very large or very strong wings like the X-34. However, the X-34 type wings do have the advantage of allowing for a gliding abort should anything go wrong in the boost phase of flight. Still, the vehicle requires active control during its gliding descent, and will not have the built-in stability of a capsule or Burt Rutan's "shuttlecock" system.
First, I must clarify that I do not want to bring down ISS, just the completed experiments.
That being said, there are good reasons for bringing down ISS experiments. For one thing, ISS hardware is too expensive to simply get thrown overboard. Discarding it also creates more debris in the orbital plane of ISS, the severity of which is determined by the mass of the experiments.
More importantly, it is naive to think that all of the scientific observation can be accomplished in space. The scientists on the ground will be better able to anaylze ISS experiments using their sophisticated lab equipment which is better than whatever can be brought into the confines of the space station. This becomes especially important when growing new drugs and crystalline structures in space. There are probably a whole host of other experiments I could think of, but the fact remains that many experiments need to come back to earth for completion.
If ISS is to survive past the shuttle retirement in 2010, it will need Kliper, CEV, or something like that to take down all of the experiments and hardware from the station. The European ATV can haul it up, but the down-mass issue is a problem without a real solution right now.
I'm surprised China is calling the rocket a "heavy lifter" if it can only put 25 tonnes or so in LEO. It's an important step forward for China as their first cryogenically-fuelled rocket, but I doubt that the rocket they'r talking about will put humans on the moon.
I think that Kliper is the right thing for the Russians to build, as an evolutionary step forward from Soyuz, and it can probably be adapted to meet the CEV requirements. Yet I remain skeptical that the Russians can actually build it. Their once-mighty space program has fallen over the past decade. The Energia-Buran system died from lack of funding (although the Buran orbiter was never practical--just look at the shuttle and ask yourself if Buran could have done much better.) Russia is relying on foreign subsidies and even space tourists just to keep up its commitment to ISS.
Is Kliper impossible? Hardly. Yet it is also a lot harder because of the dire economic situation in Russia. Foreign help may speed the process up, but it's important to remember that the Europeans as a whole have not been very willing to spend a lot of money on space either.
It would appear that the metal frame in the ITAR-TASS picture is for the Kliper mockup. A mockup is not too encouraging. After all, the American HL-20 and Russian MAKS both made it to mockup stage but no further. Even the doomed X-38 at least made it past the mockups and into the flight-test stage before it was killed.
I would like to see Kliper succeed but I would not place bets on it.